1. Field of the Invention
This invention relates to swimming pool cover systems, and in particular, to extruded swimming pool track constructs which anchor a pool cover along a pool side edges and related pulleys carrying cables for cover extension and retraction.
2. Description of the Prior Art
Swimming pool cover systems typically include covers formed from flexible vinyl fabrics or interconnected rollable (hinged) rigid buoyant slats (See U.S. Pat. No. 4,577,352 Gautheron). Such pool covers float on the water surface of the pool and are anchored/supported along the sides and ends of the pool. When covering and uncovering, pool water provides a low friction surface supporting the cover which significantly reduces the effort required to move the cover across the pool.
Typically mechanical systems are utilized to draw the cover back and forth across the pool in which a cable, typically a Dacron line, is incorporated into to form a flexible beaded edge sewn or otherwise secured to the side edges of the pool cover. The beaded edge in turn is captured and slides within a C-channel of an extruded aluminum cover track. The track is secured either to the pool deck, or the underside of an overhanging coping along the sides of the pool. In new pools, the side walls of the pool frequently are constructed with integral channels for receiving the cover track and securing vinyl pool liners. (See U.S. Pat. No. 4,967,424 Stegmeier)
The cables extending from the beaded edges at the front of the cover, are trained around pulleys at the distal ends of the tracks (See U.S. Pat. No. 4,466,144 Lamb) and return in a parallel C-channel to a drive mechanism where they wind onto and unwind from cable take-up reels. The cable take-up reels are coupled to a drive mechanism for extending the cover. To uncover the pool, the drive mechanism rotatably drives a cover drum located and secured at one end of the pool for winding the pool cover around its periphery unwinding the cables from the take-up reels. (See U.S. Pat. No. 5,799,342, Last)
The front edges of flexible vinyl covers are typically secured to and supported by a rigid leading edge spanning the width of the pool for holding the front edge of the cover above the water as it is drawn back and forth across the pool. Similarly, rollable buoyant slat covers frequently include a front or floating leading edge. Leading edges are typically secured to and mechanically supported by sliders sliding in the C-channel of the cover track coupled to the cable extending from the flexible beaded edge of the cover. (See U.S. Pat. Nos. 4,939,798 and 5,950,253 Last.) Positive stops are sometimes secured at the ends of the pool cover tracks for positively arresting translation of the sliders sliding within the C-channels carrying the rigid leading edges. (See U.S. Pat. No. 5,349,707 Last.)
Wearing components of mechanical swimming pool cover systems must be replaceable. In particular, a swimming pool is a harsh environment. The water and treating chemicals are corrosive, galvanically and otherwise. Intense sunlight exposure typical of outdoor pool exacerbates deterioration of exposed components, converting pliable vinyl plastics into flaking sharp shards. Then the sliding components of the mechanical pool cover systems tend collect and concentrate floating debris and crud at wearing interfaces. Such collected and concentrated debris and crud in turn entraps dirt, dust, and sand to transform into a flowable abrasive grit which insinuates itself into every moving component of the cover system, particularly the end pulleys and related assemblies.
Replacing end pulleys in mechanical swimming pool cover systems is a particularly irksome task. Even removable end pulleys of the type described in U.S. Pat. No. 4,446,144 Lamb are difficult to replace. In particular, as noted in Lamb while a tang extending from the assembly into a channel between the respective C-channels of the extruded track promotes alignment of pulley, the extending tang does not prevent the assembly from oscillating loose when loaded. (See Lamb (supra) Col. 5, line 25-Col. 6, line 42.) The upshot is, that in practice, even the Lamb end pulley and related housing assembly should be securely bolted to or fastened at a stationary position relative to the end of the track, otherwise the oscillating loads experienced by the pulley bend or deform the pulley housing material and/or deform the end of the track.
Then as noted in Lamb (Col. 4, lines 55 to Col. 5, line 2) because of the loads experienced by such end pulley assemblies, it is generally preferable to provided bores through the assembly through which a cable is strung rather than grooves. (Lamb does point out that if stronger materials were utilized for constructing the pulley housing, grooves would be preferred.) Lamb fails to mention attendant galvanic corrosion problems between such stronger materials and aluminum swimming pool track. As a practical matter, whenever a pulley fails, unless its housing assembly is mechanically isolated from the track end, the housing is damaged and track end deformed, simply because the typical pool owners, not knowing why a cover is not properly extending/retracting, all too frequently, will overstress the system into catastrophic failure trying to make it work.
Accordingly, when an end pulley must be replaced, the either entire cable must be unstrung through the damage pulley assembly and re-threaded through the replacement pulley assembly or the cable must be cut and then spliced. The latter alternative inevitably leads to a broken or snagged cable and a pool owner demanding a replacement.
Finally, contemplate the problems confronting a repair person attempting to replace an end pulley assembly mounted on the underside of an overhanging coping along the sides of the pool, or at the end, within an extruded aluminum channel integrated into the structural side wall of the pool. (See FIG. 1, U.S. Pat. No. 5,349,707, Last.) If water is not drained from the pool, a snorkel or scuba tank would be required.
An invented track construct component system with a threaded radial bearing end pulley is described for pool cover systems that includes:
a) an extruded longitudinal cover track having
(i) a top face with a longitudinal anchoring slot and a planar base face
(ii) a C-channel with a longitudinal slot opening along an outside side edge of the cover track for capturing and holding a side edge of a pool cover and associated sliders carrying leading (front) edge structures,
(iii) a cable return channel with a longitudinal slot opening along an inside side edge of the cover track for receiving and protecting cabling connecting between the sliders/front cover corners and associated cable reels; and
b) an extruded side wall channel structure having a top channel side wall with a depending longitudinal land and a flat, bottom channel side wall adapted for and incorporated into the structure of the side wall of the pool for receiving a cover track wherein the depending longitudinal land is shaped for snuggly fitting into the longitudinal anchoring slot of the cover track; and
c) a longitudinal spacer plate adapted for and inserted between the flat, bottom flat channel side wall of the wall channel structure and the planar base face of the cover track for mechanically holding the cover track within the wall channel with its anchoring slot snuggly receiving the depending longitudinal land of the wall channel structure, and
d) a coupling plate-radial bearing end pulley assembly fastened at the distal end of each cover track.
The distal end wall of the pool includes a similar extruded end wall channel structure for accommodating the coupling plate-radial bearing end pulley assembly fastened at the distal end of each cover track.
The coupling plate-radial bearing end pulley assembly includes a novel inner annular bearing race with interior helical threads for screwing onto a perpendicularly extending, complementarily threaded, post integral with the coupling plate. The outer annular bearing race has a concave exterior, circumferential groove for receiving, carrying and returning cabling connecting between a slider/front cover corner and a cable reel.
A primary advantage of the invented extruded track construct component system with a threaded radial bearing end pulley is that a cover track can be easily removed from a wall channel structure by simply extracting the longitudinal spacer plate allowing mechanical disengagement of the depending longitudinal land in the anchoring slot of the cover track. Once the longitudinal spacer plate is extracted, distal end of the cover track can be slid diagonally sideways out of the wall channel preferably pivoting from the opposite end of the cover track proximate a cover drum and associated cable reels of the cover drive system. In this manner the radial bearing end pulley-coupling plate assembly fastened at the distal end of the cover track is exposed for easy repair or replacement.
Other advantages of the invented system relate to the xe2x80x98thinnessxe2x80x99 and structural integrity of the radially bearing end pulley-coupling plate assembly achieved by a novel combination of a helically threaded, annular inner bearing race screwing onto a complimentary, helically threaded post for fastening the radial bearing to a coupling plate. In particular, the thickness of the end pulley-coupling plate assembly can be matched to that of the extruded pool cover track to which it is attached. Protruding shaft ends and associated retainer clips, nuts collars and the like, typical for such replaceable radial bearing end pulley assemblies are eliminated.
The invented novel combination of a helically threaded annular inner bearing race screwing onto a complimentarily threaded post as a mechanism for fastening or securing a radial bearing has similar advantages in many other types of mechanical systems utilizing radial bearings, in particular, those systems where the annular inner race of the radial bearing journals around and is stationary with respect to its mounting shaft or spindle and its annular outer race rotates relative to the inner race engaging and/or carrying a complimentary belt, cable or gear. The threaded engagement of the inner bearing race onto a post of a coupling plate eliminates the necessity for thrust bearings, annular retainer clips, bolts, collars, set screws and like typically utilized for securing such bearing assemblies onto shafts and spindles.
In mechanical systems where rotation of the radial bearing is only in one direction, the inner race and post of the invented bearing assembly can be threaded in a direction such that system rotation tightens threaded engagement of the inner race on the post.
Also in top track pool cover systems where the cover track is secured to the top surface of a deck surrounding the pool, the threaded the inner annular race of the radial bearing end pulley uniquely allows a pulley cap to be secured covering the pulley and coupling plate assembly by a complimentarily threaded flat or round head screw that screws into the inner race of the bearing.
Other features of the invented extruded track construct component system relates to post-construction utilization of plastic plug rails conventionally used to maintain the integrity of the channels of extruded wall channel structures during pool during construction, to close the channel opening of a wall channel incorporated into the distal end wall of the pool to prevent debris capable of fouling the radial bearing end pulleys assemblies from collecting in the end wall channel.
Still other features, aspects, advantages and objects presented and accomplished by invented track construct component system and associated threaded radial bearing assembly systems will become apparent and/or be more fully understood with reference to the following description and detailed drawings of preferred and exemplary embodiments.